1. Field of the Invention
This invention relates to composite wrap materials, and more particularly to composite wrap materials used primarily for packaging hot foodstuffs, with the composite wrap facilitating heat retention, moisture control and masking of food staining. The invention also relates to a method of making the composite wrap materials.
2. Background of the Invention
Composite wrap materials have long been used to package hot foodstuffs. In addition to keeping the foodstuff relatively fresh for a period of time, the wrap facilitates heat retention by the foodstuff after it is made, but before it can be consumed. Further, the wrap presents the food in an eye appealing manner.
Current commercial wraps include polyethylene coated paper, hot melt coated paper, foil/tissue laminations, dry wax, etc. Unfortunately, these wrap materials have the serious disadvantage of high moisture retention to maximize heat retention. Consequently, the wrapped, heated foodstuff becomes soggy and unpalatable. Additionally, unsightly grease produced during heating of the foodstuff can remain in the wrapped package, causing additional sogginess as well as unsightly grease stains. Even where moisture vapor is permitted to escape, for example, through semi-permeable thermoplastic films, unsightly grease may still appear on the thermoplastic film layer, and can even be reabsorbed by the food from which it originated.
Another disadvantage of known food wrap composite materials is that they all utilize only two layers (two-ply)--typically a thermoplastic layer and a second paper layer. If, for example, the second paper layer is used on the outer surface of the wrap-away from the foods to permit printing of a logo, name, descriptions, etc.--then there is no inner absorbent layer to absorb any excess vapor which may not escape through a semi-permeable thermoplastic inner layer, but which may condense on that layer and then be absorbed by the foodstuff. In addition, grease may collect on the thermoplastic layer and also be absorbed by the foodstuff. Both the condensed vapor and grease can contribute to unsightly stains and, even worse, to make the heated foodstuff soggy and unpalatable.
A good example of the above situation is illustrated in U.S. Pat. No. 4,515,840. This patent teaches a layer generally adjacent the foodstuff which is a thermoplastic material, semi-permeable to water vapor but not grease while the outer layer is a printable paper. As discussed above, there would be no inner layer to absorb condensed water vapor which did not pass through the semi-permeable thermoplastic material and, more importantly, no inner layer to catch or absorb any grease from the hot foodstuff. In either case, the grease or condensed water vapor would necessarily return to the foodstuff thereby making it soggy and unpalatable.
If, as also disclosed in U.S. Pat. No. 4,515,840, the paper layer is adjacent to the foodstuff and the second, outer layer is the thermoplastic material, there would be no outer layer for purposes of printing indicia or other identifying marks. Furthermore, in both cases there is the more serious disadvantage in that the heated foodstuff is giving off its own heat via the water vapor which is allowed to pass through the semi-permeable thermoplastic material, thereby permitting the foodstuff to cool off.
Accordingly, there is presently a need to develop a composite wrap material capable of overcoming the aforementioned deficiencies. In addition, there is a need to develop a method of manufacturing this composite wrap material.